1. Field of the Invention
The present invention relates to a digital copier being provided with a memory function which enables a plurality of copying conditions to be set by a single setting operation before copying operations are initiated and which also enables the copying conditions to be changed during the copying operations.
2. Description of Related Art
With conventional analog copiers or digital copiers without a memory function, an operator is expected to set a plurality of conditions relating to copying, such as the number of copies, sorting or non-sorting, and image quality, before pressing a start key. In the case where the operator notices an error in the setting of the copying conditions, he or she is expected to press a clear/stop key or the like immediately, wait for the current copying operation to be completed, reset the copying conditions, and then press the start key again so as to resume copying. In the case where sorting is to be performed, the document is discharged after it is scanned to provide the specified number of copies.
Thus, the conventional analog copiers or digital copiers without a memory function are disadvantageous in that, when an error is noticed in the setting of the copying conditions after the copying is initiated, a considerable period of time is required to resume the copying. Moreover, since the document is discharged while sorting is being performed, it is substantially impossible to change the number of copies after the copying is initiated.
Some of these conventional copiers are provided with various functions convenient for operators, among which are: an automatic paper selecting function for automatically detecting the size of the document being set and selecting the proper paper to be printed in accordance with the detected size; an automatic magnification selecting function for automatically detecting the size of the document being set and setting the magnification for copying in accordance with the paper to be printed; a parallel copying function based on a 2in-1 mode; and a double-side copying function. In the case where a plurality of copies are to be produced for a document, it may be required to selectively vary the copying magnification for some of the copies or to produce copies in parallel based on the 2in-1 mode as well as to produce all the copies in the same mode. For example, it may be preferred in a record of proceedings to print a notice of holding a conference and its agenda on a sheet of paper for some copies, while, for the other copies, printing the notice of holding the conference on one half of a sheet so that the other blank half is used for taking notes. This type of copying can be performed by utilizing the parallel copying in the 2in-1 mode. Or it may be preferred to print a document image on one side of a sheet for some copies while printing it on both sides of a sheet for the other copies.
The above-mentioned parallel copying in the 2in-1 mode can be performed by means of an automatic two-document feeder. Typically, two documents are automatically fed and set on an document stand so that they are printed in parallel on a single sheet of paper. When the documents are of A4 size, for example, they are copied in parallel on a A3-sized sheet of paper. Furthermore, it is also possible to copy the two documents in parallel on a A4-sized sheet by reduction, if designated as such.
In the case where copying is to be performed by varying the copying modes for different purposes, the conventional copiers are disadvantageous, as described above, in that they require the following procedures. That is, after copying is performed in a copying mode, the operator is required to reset the document on the document stand and change the current copying mode to another copying mode before resuming the copying. It is impossible with the conventional copier to set a plurality of modes by a single setting operation. Hence, the conventional copier cannot save the labor of resetting the document and the intricate operation of changing modes after the copying operation in the first mode is completed.
There is another type of conventional copier being provided with a circulation-type automatic document refeeder for automatically refeeding the document that has been discharged after its image was scanned. With such a conventional apparatus, it is possible, to some extent, to perform copying operations in a plurality of copying modes if paper for sorting jobs in accordance with the jobs is used to specify the jobs. However, it is also impossible to save the intricate operations of setting the document-sorting paper together with a group of documents and of removing it after the copying. Moreover, since it is required to equip the copier with an extra device for detecting the document sorting paper, the constitution of the copier becomes complicated accordingly.
In a conventional analog copier, on the other hand, the scanning of an document should be performed in synchronism with a copying operation, so that the scanning operation should be repeated by the number of copies being set. This causes the reduction in lifetime of the copier, and the problems of a noise during the copying operations and increased power consumption of the copier are inevitably caused.